The invention claimed and disclosed herein pertains to inkjet imaging apparatus, and more specifically, to methods and apparatus for cleaning print heads of inkjet imaging apparatus.
Many types of prior art imaging apparatus are known. The term xe2x80x9cimaging apparatusxe2x80x9d generally encompasses any device that is configured to produce an image on an imaging media such as paper or the like. Imaging apparatus are employed in various types of devices including printers, photocopiers, facsimile machines, and the like, as well as combinations thereof which are capable of performing multiple functions. The two main categories of imaging apparatus are those of impact and non-impact imaging apparatus. Impact imaging apparatus include both the dot matrix and the character types. Non-impact imaging apparatus include inkjet, laser, solid ink, dye-sublimation, thermal wax, and thermal auto-chrome types of imaging apparatus. One of the most popular types of imaging apparatus is that of the inkjet, because of its relatively low cost and its capability to produce relatively high-quality images.
Inkjet imaging apparatus employ one or more nozzles to spray very small, individual droplets of ink onto the imaging media to form the image. These droplets can be generated in any of a number of different manners, such as by thermally heating the ink in the nozzle to cause it to boil, or by oscillating a piezoelectric crystal in the nozzle to force ink from the nozzle. Each droplet of ink that is sprayed by the nozzle forms a corresponding ink spot on the imaging media. The spots are extremely small and generally blend together to form the overall image on the imaging media. Monochromatic inkjet imaging apparatus are generally used for printing only text and/or monochromatic graphics, and employ a single color of ink, which is usually black. Color inkjet imaging apparatus are capable of producing images containing any of a wide range of colors. Such color inkjet imaging apparatus generally employ several colors of ink which usually include the colors of cyan, magenta, yellow, and black.
Inkjet imaging apparatus include at least one print head that supports one or more ink nozzles. The inkjet imaging apparatus also includes an imaging media feed system and a print head control system. The imaging media feed system, in conjunction with a controller or the like, is configured to feed the imaging media along a media path in a precisely and accurately controlled manner. The imaging media feed system generally comprises a plurality of feed rollers which are driven by a stepper motor or the like, and which contact the imaging media to feed the imaging media along the media path.
The print head control system, on the other hand, is configured to move the print head laterally across the media path, also in a precisely and accurately controlled manner. In order to perform this task, the print head control system generally comprises a lateral positioning mechanism that generally includes a stabilizer bar and a belt that is attached to the print head and driven by a stepper motor or the like. The controller, which is mentioned above, is generally employed to control the actuation of the stepper motor in a precisely and accurately controlled manner so as to position the print head relative to the imaging media.
Thus, to produce an image on the imaging media, the controller for the inkjet imaging apparatus causes the imaging media control system to move the imaging media along the media path while also causing the print head control system to move the print head laterally across the media path. While this occurs, the controller also causes the print head to spray droplets of ink from the ink nozzle onto the imaging media. That is, as the imaging media is advanced along the media path, the print head traverses across the imaging media while the ink nozzle sprays ink droplets onto the imaging media. The image is thus formed by way of precise and accurate control of the movement of both the print head and the imaging media, as well as precise and accurate control of the ink spray from the ink nozzle.
Most prior art inkjet imaging apparatus include a service station. The service station is an area where the print head, or heads, are xe2x80x9cparkedxe2x80x9d when not in use. Some prior art inkjet imaging apparatus service stations are equipped to perform cleaning operations to the print head to remove residual amounts of ink from the ink nozzle area. Residual ink can build up in the area of the ink nozzles as the result of the ink spraying operation performed by the nozzles. Such residual amounts of ink can clog the ink nozzle or impede the proper trajectory of the ink droplets as they are sprayed from the ink nozzle to the imaging media. Clogged ink nozzles and/or impeded flow of the ink droplets can result in various deleterious effects including degraded image quality and increased buildup of residual ink in the area surrounding the nozzle. Although the prior art inkjet imaging apparatus can produce satisfactory images, several disadvantages can be associated with the service stations that are often included in prior art inkjet imaging apparatus.
A primary disadvantage that can be associated with the prior art inkjet imaging apparatus service stations is that of size. That is, a significant portion of a typical prior art inkjet imaging apparatus having a service station is dedicated to accommodating the inclusion of the service station in the imaging apparatus. In other words, the inclusion of a service station in prior art inkjet imaging apparatus generally adds significantly to the overall size of the apparatus. Additionally, the results of inkjet nozzle cleaning operations associated with the prior art inkjet imaging apparatus service stations are sometimes less than satisfactory.
What is needed then are information system methods and apparatus which achieve the benefits to be derived from similar prior art methods and/or devices, but which avoid the shortcomings and detriments individually associated therewith.
The present invention provides for cleaning the print head of an inkjet imaging apparatus by utilizing imaging media as a cleaning device. More specifically, in accordance with the present invention, an imaging media and the nozzle area of a print head of an inkjet imaging apparatus are brought into contact with one another, wherein during such contact the nozzle area is moved across the media to xe2x80x9cscrubxe2x80x9d or remove contaminants and foreign matter, such as dried ink, from the nozzle area. Also in accordance with the present invention, ink from the print head can be sprayed onto the media before the nozzle are and media are brought into contact, wherein the wet ink has a solvent effect during the scrubbing process.
In accordance with one embodiment of the present invention, an in inkjet imaging apparatus includes an actuating mechanism that is configured to bring the nozzle area and the media into contact with one another for the scrubbing process. The actuating mechanism can be configured to move the print head into contact with the media while the media remains on the media path. Alternatively, the actuating mechanism can be configured to move the media off of the media path and into contact with the nozzle area.
These and other aspects and embodiments of the present invention will now be described in detail with reference to the accompanying drawings, wherein: